The present disclosure generally relates to a system suitable for automatically performing a skin prick analysis and, in particular, relates to a system suitable for automatically performing a skin prick analysis by pricking the skin of a human, or animal, subject to produce a sample of body liquid and to detect the presence, or concentration, of one or more constituents, or analytes, in the sample liquid. Depending on the skin site used and on the lancing depth, the body liquid can be blood or interstitial liquid or a mixture thereof.
Analysis based on skin-piercing can be important in several fields of medical diagnostics and treatment. One area of particular importance is the field of diabetes management. It has been determined that severe long term damages caused by diabetes mellitus can be avoided if the patient can control her/his blood sugar level several times a day in order to adapt the required insulin injections closely to the actual need for maintaining a constant blood sugar level. This control requires so called “home-monitoring” by the patient himself, or by other people not having a medical training.
Analysis systems used in this context generally comprise a particular type of disposable analysis element, such as, for example a test strip, and an instrument adapted to the analysis element and suitable for evaluating results of an analytical reaction occurring therein. The analysis element can include a reagent system which reacts with the analyte contained in the sample, thereby producing a measurable change of a measurement quantity characteristic for the desired analytical result. Generally, two types of such analysis systems are known, namely optical systems in which the measurement quantity is a color change, or other optically measurable quantity, and electrochemical systems in which the measurement quantity is an electrical current or other electrically measurable quantity. The change of the measurement quantity resulting from the reaction can be measured and evaluated by the instrument belonging to the analysis system, thereby producing the desired analytical result.
In addition to diabetes management, other important fields of medical diagnostics and treatment with similar requirements, including home-monitoring, exist. These can refer, for example, to the regular control of blood cholesterol and to the control of blood coagulation parameters. Similar situations can also exist, e.g., in so called “near-patient-testing”.
In earlier skin prick analysis systems, a plurality of steps typically had to be performed by the user, including a skin prick step, using a lancing instrument, and a separate analysis step, using an analysis element of the analysis system. Between the two steps, a transfer of the sample from the skin to the analysis element was necessary.
In order to overcome the problems caused by the complicated two step-handling, automatic skin prick analysis systems have been developed. Such systems can allow the performance all steps required for the skin prick analysis in a fully automatic operation in particular without any sample transfer handling steps of the user. Occasionally, such systems are designated “G&M-systems” because they allow the “getting” (G) of the required sample and the “measuring” (M) of the desired analytical value without user intervention.
Most G&M-systems operate with an integral lancing and analysis element, also designated as “test element”. The two components of such test elements, a lancing element and an analysis element, are generally manufactured separately but assembled by the manufacturer or at least before use, i.e., before the lancing movement is triggered. In the instrument belonging to the system such elements are processed as a unified item. In other G&M systems, separate lancing and analysis elements are provided and processed separately during at least a part of the analytical procedure.
These known approaches reflect a basic problem of G&M systems, namely the complexity of the handling steps required for a fully automatic analysis. Some of the prior art approaches concentrate only on a particular design of test element, such as, for example, integral lancing and analysis element, but provide no solution to how the test elements should be handled in a comfortable manner by an instrument belonging to the respective analysis system. For example, such prior art systems require that the test element be manually inserted into the instrument for each analysis.
Some systems provide a more comfortable solution by using a cartridge or magazine containing a plurality of test elements. Such systems provide an improved comfort because a plurality of analyses can be performed automatically without a need for the user to perform any manual handling steps other than pressing the instrument to her or his finger or other body part and triggering the operation of the instrument. However, these systems require generally a large volume and weight in order to allow for the electromechanical realization of all the movement steps required for a fully automatic analysis.
It has been found one important improvement regarding the contradictory requirements of user comfort, on the one hand, and small size and weight, on the other hand, can be achieved if movements required inside the instrument for automatically performing the analysis are driven by manually generated force, i.e. without an electric motor or consumption of electrical energy, using only a small battery for measurement—and evaluation electronics.
Therefore, there is a need for an improved system for automatically performing a skin prick analysis with maganized lancing elements.